- METHOD OF MAKING PERFLUOROCYCLOBUTANE-CONTAINING MONOMER
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The invention pertains to a multi-step process for making polyfunctional aromatic compounds comprising two phenyl rings bearing reactive groups susceptible of polycondensation reaction to provide polycondensed polymers, said method using economic raw materials, and possessing high selectivity and overall yield.
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Paragraph 0067
(2020/11/30)
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- Tetraarylphosphonium perfluorocyclobutyl polyelectrolyte with low critical surface energy, high thermal stability, and high alkaline resistance
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Two tetraarylphosphonium polyelectrolytes having perfluorocyclobutyl units in their backbones have been prepared in which the counteranion is either bromide (PFP·Br) or bis(trifluoromethyl)sulfonimide (PFP·NTf2). These polymers exhibit high thermal stability as assessed by thermogravimetric analysis, with a decomposition temperature of 460 °C for PFP·NTf2. Even after heating at 300 °C for 72 h, PFP·NTf2 shows no signs of degradation detectable by nuclear magnetic resonance spectrometry. As is typical for many tetraarylphosphonium species, films of these polymers can be quite resistant to degradation by alkaline solution. Upon alkaline challenge by exposure to 6 M NaOH at 65 °C for 24 h, for example, only 16% of the phosphonium centers in PFP·NTf2 are degraded, making PFP·NTf2 one of the most alkaline-stable phosphonium polymers to date. Despite having ionic backbones, PFP·Br and PFP·NTf2 exhibit very low critical surface energies of 26.1 and 22.9 mJ m?1, respectively. These values are on par with the values for poly(vinylene fluoride) and dimethylsiloxane. Such low surface energy polycations capable of high alkaline stability may find application as components of alkaline fuel cell membranes.
- Wan, Wang,Bedford, Monte S.,Smith, Rhett C.
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p. 2267 - 2272
(2019/11/14)
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- Method for preparing trifluorovinyl aryl ether compound from dihalide trifluoroethane
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The invention relates to a method for synthesizing a trifluorovinyl aryl ether compound, and belongs to the field of chemical synthesis. The dihalide trifluoroethane is taken as the starting material, reacts with a phenolic compound under proper conditions to synthesize the trifluorovinyl aryl ether compound. Compared with the traditional method, the provided synthesis method has the characteristics of mild reaction condition, simple operation, moderate yield and the like, has the advantages of simple process, low cost, low pollution and the like, and is expected to realize industrialized production.
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Paragraph 0026-0032
(2017/08/29)
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- Method for compounding synthetic trifluorovinyl aryl ether compound and application thereof
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The invention provides a convenient and high-efficient method for compounding synthetic trifluorovinyl aryl ether compound and an application thereof. Particularly, the invention provides a trifluorovinyl aryl ether compound with formula Ia structure and a trifluorovinyl aryl ether structure unit with formula Ib structure, and an application thereof; definition of every radical in the formula is the same as the description in a specification. The preparation method of the Ia and Ib structural compounds include steps of removing aryl trifluorovinyl ester, and thereby forming the trifluorovinyl aryl ether compound. Ar-(OCF=CF2)n(Ia)-Ar-(OCF=CF2)N(Ib).
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Paragraph 0172; 0173; 0174
(2017/07/18)
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- Nucleophilic tetrafluoroethylation employing in situ formed organomagnesium reagents
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Tetrafluoroalkyl bromides are metalated with equimolar iPrMgCl·LiCl (Turbo Grignard) to form organomagnesium compounds which are stable at low temperatures and react with various electrophiles (aldehydes, ketones, CO2, cyclic sulfate and sulfamidate, N-sulfonylimines, nitrone, chlorophosphate, nonaflyl azide) to afford novel functionalized tetrafluoroethylene-containing products. Ease of operation, excellent selectivity, high nucleophilicity, and enhanced stability of the reactive species together with a broad substrate scope comprise a highly attractive nucleophilic tetrafluoroethylation protocol affording unique synthetic building blocks.
- Budinská, Alena,Václavík, Ji?í,Matou?ek, Václav,Beier, Petr
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supporting information
p. 5844 - 5847
(2016/11/29)
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- Postpolymerization of functional organosiloxanes: An Efficient strategy for preparation of low-k material with enhanced thermostability and mechanical properties
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A novel functional oligomer (Si-TFVE) with a siloxane backbone and thermally cross-linkable trifluorovinyl ether groups (-OCF=CF2) is reported here. When postpolymerized at high temperature, Si-TFVE converts to an amorphous cross-linked network (Si-PFCB), which shows a dielectric constant of 2.33 and dielectric loss below 2.1 × 10-3 at 30 MHz. Si-PFCB also shows excellent film uniformity with the surface roughness less than 5.79 nm over a 1 μm square area. Moreover, Si-PFCB shows high thermostability with a 5 wt % loss temperature of 472°C and no obvious Tg below 350°C. In regard to the mechanical properties, Si-PFCB has Young's modulus, hardness, and bonding strength with silicon wafer surface of 10.06 GPa, 0.392, and 4.93 GPa, respectively. These results suggest that such oligomer is suitable for utilization in ultralarge scale integration circuits. In addition, this contribution provides a new route to prepare cross-linked organosiloxanes only by heating instead of using catalysts or initiators in the traditional procedures. (Chemical Equation Presented).
- Yuan, Chao,Wang, Jiajia,Jin, Kaikai,Diao, Shen,Sun, Jing,Tong, Jiawei,Fang, Qiang
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p. 6311 - 6315
(2015/02/19)
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- Fluorinated aromatic polyether ionomers containing perfluorocyclobutyl as cross-link groups for fuel cell applications
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The cross-linkable copolymers (SHQx-TFVys) with varying degrees of sulfonation (DS) from 70 to 95% were prepared from potassium-2,5- dihydroxybenzenesulfonate (SHQ), decafluorobiphenyl (DFBP), and 4-(trifluorovinyloxy)-biphenyl-2,5-diol (TFVOH) as a cross-linkable moiety. To develop a highly stable polymer electrolyte membrane (PEM) for application in polymer electrolyte fuel cells (PEFC)s, cross-linked membranes were prepared by chemical cross-linking. The cross-linked membranes were synthesized by varying the amount of TFVOH (5-30 mol %) in order to achieve desirable PEM properties. The structures of the cross-linkable monomer and polymers were investigated by 1H and 19F NMR and FT-IR spectra. The cross-linked membranes exhibited good glass transition temperature and thermal stability up to 239-271 °C and 290-312 °C, respectively. The crosslinked membranes (DS range 80-95%) exhibited higher proton conductivity(0.098-0.151 S/cm) than Nafion 212 (0.092 S/cm). Moreover, all membranes possessed lower methanol permeability (13-132 × 10-8 cm2/s) compared with Nafion 212 (163 ×10-8 cm2/s) under the same measurement conditions. The H2/O2 single cell performance tests of the cross-linked membranes and Nafion 212 were performed. The CSHQ90-TFV10 exhibited the higher maximum power density (1.053 W/cm2) than that of Nafion 212 (0.844 W/cm2).
- Lee, Kwan-Soo,Jeong, Myung-Hwan,Kim, Young-Jea,Lee, Su-Bin,Lee, Jae-Suk
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scheme or table
p. 1443 - 1453
(2012/07/28)
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- Novel fluorinated poly(aryl ether)s derived from 1,2-bis(4-(4-fluorobenzoyl)phenoxy)-hexafluorocyclobutane
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Two novel poly(aryl ether)s were prepared from 1,2-bis(4-(4-fluorobenzoyl)-phenoxy)-hexafluorocyclobutane and aromatic bisphenols by the aromatic nucleophilic substitution reaction in a polar aprotic solvent. These polymers have good thermal stability up to 341 °C with 10% weight loss in inert atmosphere and good solubility in common organic solvents such as THF, DMAc, DMF and DMSO.
- Zhou, You,Qing, Feng-Ling
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p. 498 - 502
(2008/12/22)
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- Perfluorocyclobutyl (PFCB) aromatic polyethers: Synthesis and characterization of new sulfonimide containing monomers and fluoropolymers
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The synthesis and thermal cyclopolymerization of aryl trifluorovinyl ether monomers containing novel sulfonimide acid functionalities are described. The monomers are prepared starting from commercially available 4-bromophenol in five steps. These novel polymers explore a new versatile class of partially fluorinated polymers for potential use in fuel cells and other electrochemical applications.
- Ford,DesMarteau,Smith Jr.
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p. 653 - 660
(2007/10/03)
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- Synthesis and Characterization of Phenylphosphine Oxide Containing Perfluorocyclobutyl Aromatic Ether Polymers for Potential Space Applications
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A novel class of phenylphosphine oxide (PPO) containing perfluorocyclobutyl (PFCB) polymers has been developed for potential use as multifunctional materials in space environments. The reaction of p-BrArOCF=CF2 (for Ar = phenyl and biphenyl) with tert-butyllithium affords the lithium reagent smoothly below -20 °C. Subsequent substitution with phenylphosphonic dichloride provides the first bis(trifluorovinyl ether) monomers containing the PPO group. Polymerization proceeds thermally above 150 °C to give polymers that exhibit glass transition temperatures of 169 and 224 °C, respectively, and catastrophic weight loss by TGA in N2 and air above 450 °C (10 °C/min). Copolymerization with bis(4,4′-trifluorovinyloxy)biphenyl affords film-forming transparent thermoplastic copolymers with high Tg (>140 °C) and good thermal stability (>450 °C). Initial evaluations with ground-based simulation of atomic oxygen (AO) rich space environments indicate that the PPO group imparts significant space durability to PFCB polymers.
- Jin, Jianyong,Smith Jr., Dennis W.,Topping, Chris M.,Suresh,Chen, Shengrong,Foulger, Stephen H.,Rice, Norman,Nebo, Jon,Mojazza, Bob H.
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p. 9000 - 9004
(2007/10/03)
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